Re: [PATCH 14/16] ehca: queue page table handling

On Mon, 15 May 2006 19:43:09 +0200 Heiko J Schick wrote:

+/*  return current Queue Page , increment Queue Page iterator from
+ *   page to page in struct ipz_queue, last increment will return 0! and
+ *   NOT wrap
+ *   returns address (kv) of Queue Page
+ *   warning don't use in parallel with ipz_QE_get_inc()
+ */

When not using kernel-doc format... the preferred multi-line
comment format is:

/*
 * foo foo foo ........
 * bar bar bar .......
 * blahz ..........
 */

repeat below.

+void *ipz_qpageit_get_inc(struct ipz_queue *queue);
+
+/*  return current Queue Entry, increment Queue Entry iterator by one
+ *   step in struct ipz_queue, will wrap in ringbuffer
+ *   @returns address (kv) of Queue Entry BEFORE increment
+ *   warning don't use in parallel with ipz_qpageit_get_inc()
+ *   warning unpredictable results may occur if steps>act_nr_of_queue_entries
+ */
+static inline void *ipz_qeit_get_inc(struct ipz_queue *queue)
+{
+	void *ret = NULL;
+
+	ret = ipz_qeit_get(queue);
+	queue->current_q_offset += queue->qe_size;
+	if (queue->current_q_offset >= queue->queue_length) {
+		queue->current_q_offset = 0;
+		/* toggle the valid flag */
+		queue->toggle_state = (~queue->toggle_state) & 1;
+	}
+
+	EDEB(7, "queue=%p ret=%p new current_q_addr=%lx qe_size=%x",
+	     queue, ret, queue->current_q_offset, queue->qe_size);
+
+	return ret;
+}
+
+/*  return current Queue Entry, increment Queue Entry iterator by one
+ *   step in struct ipz_queue, will wrap in ringbuffer
+ *   returns address (kv) of Queue Entry BEFORE increment
+ *   returns 0 and does not increment, if wrong valid state
+ *   warning don't use in parallel with ipz_qpageit_get_inc()
+ *   warning unpredictable results may occur if steps>act_nr_of_queue_entries
+ */
+static inline void *ipz_qeit_get_inc_valid(struct ipz_queue *queue)
+{
+	struct ehca_cqe *cqe = ipz_qeit_get(queue);
+	u32 cqe_flags = cqe->cqe_flags;
+
+	if ((cqe_flags >> 7) != (queue->toggle_state & 1))
+		return NULL;
+
+	ipz_qeit_get_inc(queue);
+	return cqe;
+}
+

+/* destructor for a ipz_queue_t
+ *  -# free queue
+ *  see ipz_queue_ctor()
+ *  returns true if ok, false if queue was NULL-ptr of free failed
+ */
+int ipz_queue_dtor(struct ipz_queue *queue);
+
+/* constructor for a ipz_qpt_t,
+ * placement new for struct ipz_queue, new for all dependent datastructors
+ *
+ *  all QP Tables are the same,
+ *  flow:
+ *  -# allocate+pin queue
+ *  -# initialise ptcb
+ *  -# allocate+pin PTs
+ *  -# link PTs to a ring, according to HCA Arch, set bit62 id needed
+ *  -# the ring must have room for exactly nr_of_PTEs
+ *  see ipz_qpt_ctor()
+ */
+void ipz_qpt_ctor(struct ipz_qpt *qpt,
+		  const u32 nr_of_QEs,
+		  const u32 pagesize,
+		  const u32 qe_size,
+		  const u8 lowbyte, const u8 toggle,
+		  u32 * act_nr_of_QEs, u32 * act_nr_of_pages);
+
+/*  return current Queue Entry, increment Queue Entry iterator by one
+ *   step in struct ipz_queue, will wrap in ringbuffer
+ *   returns address (kv) of Queue Entry BEFORE increment
+ *   warning don't use in parallel with ipz_qpageit_get_inc()
+ *   warning unpredictable results may occur if steps>act_nr_of_queue_entries
+ *
+ *   fix EQ page problems
+ */
+void *ipz_qeit_eq_get_inc(struct ipz_queue *queue);
+
+/*  return current Event Queue Entry, increment Queue Entry iterator
+ *   by one step in struct ipz_queue if valid, will wrap in ringbuffer
+ *   returns address (kv) of Queue Entry BEFORE increment
+ *   returns 0 and does not increment, if wrong valid state
+ *   warning don't use in parallel with ipz_queue_QPageit_get_inc()
+ *   warning unpredictable results may occur if steps>act_nr_of_queue_entries
+ */
+static inline void *ipz_eqit_eq_get_inc_valid(struct ipz_queue *queue)
+{
+	void *ret = ipz_qeit_get(queue);
+	u32 qe = *(u8 *) ret;
+	EDEB(7, "ipz_QEit_EQ_get_inc_valid qe=%x", qe);
+	if ((qe >> 7) == (queue->toggle_state & 1))
+		ipz_qeit_eq_get_inc(queue); /* this is a good one */
+	else
+		ret = NULL;
+	return ret;
+}

---
~Randy